Various work operations require that a part or member be rotated with precision. In the medical field such a function is commonly carried out by a driver which should be capable of receiving several different types of instruments. A driver is used, for example, in surgery to drill a hole in a bone and to drive a wire into portions of a bone separated by a fracture.
Normally in the use of the driver as a power source for surgical procedures, the power source should have sufficient versatility to be usable with different types of instruments. For example, when used with a wire driving instrument, several different instruments may be used in one procedure because of the need to use wires of different size. Thus, instruments must be changed quickly and mounted properly for accurate driving. In any surgical procedure in which the patient is under anesthesia, the surgeon prefers to complete the procedure quickly since the length of time under anesthesia should be reduced, if possible. Where time is consumed during a procedure due solely to the time needed to change instruments by use of separate key locking members, or relatively complex manipulations, there is objection. Moreover, the surgical procedure sometimes results in fluids contacting the driver or the instruments or both so that it is difficult to turn elements on the driver or instrument for the purpose of adjust or change of instruments.
For example, a driver having a round handle may tend to slip if the surgeon's gloves are wet. Slippage because of wet gloves may also render more difficult the task of changing instruments.
One of the more practical problems to provide a driver which may be used with a wire driving instrument, that is, a tool used as a power source to rotate an instrument which engages a wire to be driven into bone structure as is frequently performed during osteological procedures. The same driver may later be used in a different procedure, e.g. a skull puncture. In wire driving, the length of wire may vary, in some instances the wire may be as long as 15 to 20 centimeters. Thus, the driver itself must be capable of receiving such a wire, while still achieving the objective of compatibility with other instruments which must be accurately aligned, securely held and properly driven. Any "wobble" of the driven instrument must be avoided.
Due to the versatility needed in such a driver, the release mechanism which must be actuated to change instruments should be easily operated, but not positioned in such a location that it may be accidentally actuated to release an instrument during a surgical procedure.
A driver typically includes a handle or hand piece which is adapted to be manually grasped and a barrel which extends transverse to the handle. The barrel typically contains the air motor and a rotatable member such as a chuck.
One problem with this construction is that for wire drilling, the barrel should be open so that the wire can be fed through it from the rear to the front. This creates a problem when the air motor is mounted within the barrel. One prior art driver employs an air motor in the handle but this driver is foot controlled and the air motor is removable from the handle.
Any driver which is foot controlled is subject to the criticism that it limits the mobility of the surgeon, i.e. the surgeon must always stand close to the foot switch and if the surgeon must move away from the switch, for some reason, the switch must be located before the procedure can be resumed. A driver with a pistol grip control overcomes this disadvantage. Where such a tool also permits considerable versatility, to the extent of receiving a wire driving instrument, and easy interchange of instruments, a truly unique surgical power source is provided.